Changing the name would create a new timeline. Changing your socks would create a new timeline, from one where you didn't. The name change resulted from Picard and the Ent E being back in time for the events of "First Contact". This explains why the crew of Voyager, upon seeing the fake starship labled NX-01, Dauntless, didn't dismiss it as an obvious hoax. Voyager's crew and memory banks were unaffected by the change to the timeline because they themselves were temporarily absent from the "present" when the timeline changed as they were in the past dealing with Henry Starling. And speaking of Henry Starling, did all the advances in computer technology he introduced cause anything to change. We know that Janeway said "This was part of our past" but hey.................